RF thermal fuse

Abstract

Certain aspects are directed to a thermal fuse for preventing overheating of RF devices in a telecommunication system. The RF thermal fuse includes a body, a conductive bolt, and a driving mechanism. The body can be positioned on a transmission line between an RF signal source and an RF device. The conductive bolt is positioned in the body. The conductive bolt has a length sufficient to provide impedance at a point of protection on the transmission line in response to the conductive bolt contacting a live conductor of the transmission line. The impedance is sufficient to reflect a portion of the incident power of an RF signal from the RF source. The driving mechanism can cause the conductive bolt to contact the live conductor in response to a temperature at or near the point of protection exceeding a threshold temperature.

What is claimed is: 
     
       1. An RF thermal fuse comprising:
 a body; 
 a conductive bolt positioned in the body, the conductive bolt having a length sufficient to provide an impedance at a point of protection on a transmission line in response to the conductive bolt contacting a live conductor of the transmission line, wherein the impedance reflects a portion of the incident power of an RF signal from an RF signal source; and 
 a driving mechanism that causes the conductive bolt to contact the live conductor in response to a temperature at or near the point of protection exceeding a threshold temperature. 
 
     
     
       2. The RF thermal fuse of  claim 1 , wherein the driving mechanism is irreversible. 
     
     
       3. The RF thermal fuse of  claim 2 , wherein the driving mechanism comprises:
 a spring that applies a force to the conductive bolt in a direction toward the live conductor; and 
 a solder that resists the force applied to the conductive bolt, wherein the solder comprises a soldering material having a melting temperature equal to the threshold temperature. 
 
     
     
       4. The RF thermal fuse of  claim 1 , wherein the driving mechanism is reversible. 
     
     
       5. The RF thermal fuse of  claim 4 , wherein the driving mechanism comprises a bimetal driving mechanism. 
     
     
       6. The RF thermal fuse of  claim 4 , wherein the driving mechanism comprises a chamber enclosing a gas or liquid, wherein the gas or the liquid is expandable such that the gas or the liquid applies pressure to the conductive bolt in response to the threshold temperature. 
     
     
       7. The RF thermal fuse of  claim 4 , wherein the driving mechanism comprises an electromagnet that opposes a force applied by a spring to the conductive bolt in a direction toward the live conductor in response to the electromagnet receiving a current from the RF device. 
     
     
       8. The RF thermal fuse of  claim 4 , wherein the driving mechanism comprises a shape memory alloy spring mechanism. 
     
     
       9. The RF thermal fuse of  claim 1 , further comprising a dielectric material positioned at a first end of the conductive bolt opposite a second end of the conductive bolt that contacts the live conductor. 
     
     
       10. A thermal protection system comprising:
 a plurality of RF thermal fuses, each RF thermal fuse comprising: 
 a body positioned on a transmission line between an RF signal source and an RF device; 
 a conductive bolt positioned in the body, the conductive bolt having a length sufficient to provide an impedance at a point of protection on the transmission line in response to the conductive bolt contacting a live conductor of the transmission line; and 
 a driving mechanism that causes the conductive bolt to contact the live conductor in response to a temperature at or near the point of protection exceeding a threshold temperature; 
 wherein the plurality of RF thermal fuses are positioned on the transmission line at intervals such that the plurality of RF thermal fuses provide a combined impedance that reflects a portion of the incident power of an RF signal in a predetermined frequency band from the RF signal source. 
 
     
     
       11. The thermal protection system of  claim 10 , wherein, for at least one of the plurality of RF thermal fuses, the driving mechanism is irreversible. 
     
     
       12. The thermal protection system of  claim 11 , wherein the driving mechanism comprises:
 a spring that applies a force to the conductive bolt in a direction toward the live conductor; and 
 a solder that resists the force applied to the conductive bolt, wherein the solder comprises a soldering material having a melting temperature equal to the threshold temperature. 
 
     
     
       13. The thermal protection system of  claim 10 , wherein, for at least one of the plurality of RF thermal fuses, the driving mechanism is reversible. 
     
     
       14. The thermal protection system of  claim 13 , wherein the driving mechanism comprises a bimetal driving mechanism. 
     
     
       15. The thermal protection system of  claim 13 , wherein the driving mechanism comprises a chamber enclosing a gas or liquid, wherein the gas or the liquid is expandable such that the gas or the liquid applies pressure to the conductive bolt in response to the threshold temperature. 
     
     
       16. The thermal protection system of  claim 13 , wherein the driving mechanism comprises an electromagnet that opposes a force applied by a spring to the conductive bolt in a direction toward the live conductor in response to the electromagnet receiving a current from the RF device. 
     
     
       17. The thermal protection system of  claim 13 , wherein the driving mechanism comprises a shape memory alloy spring mechanism. 
     
     
       18. The thermal protection system of  claim 10 , wherein each of the plurality of RF thermal fuses further comprises a dielectric material positioned at a first end of the conductive bolt opposite a second end of the conductive bolt that contacts the live conductor. 
     
     
       19. A system comprising:
 an RF device in communication with an RF signal source via a transmission line; 
 an RF thermal fuse positioned on the transmission line, the RF thermal fuse comprising: 
 a body positioned on the transmission line between the RF signal source and the RF device; 
 a conductive bolt positioned in the body, the conductive bolt having a length sufficient to provide an impedance at a point of protection on the transmission line in response to the conductive bolt contacting a live conductor of the transmission line, wherein the impedance reflects a portion of the incident power of an RF signal from the RF signal source; and 
 a driving mechanism that causes the conductive bolt to contact the live conductor in response to a temperature at or near the point of protection exceeding a threshold temperature. 
 
     
     
       20. The system of  claim 19 , wherein the RF device comprises a thermal over-temperature protection fuse coupled to at least one component of the RF device, wherein a signal path is provided from the transmission line to the thermal over-temperature protection fuse via the at least one component, wherein the thermal over-temperature protection fuse opens the signal path in response to a temperature of the at least one component exceeding the threshold temperature. 
     
     
       21. The system of  claim 20 , wherein the thermal over-temperature protection fuse comprises a soldering material that electrically connects the thermal over-temperature protection fuse to the at least one component, wherein the soldering material has a melting temperature less than or equal to the threshold temperature. 
     
     
       22. An RF thermal fuse comprising:
 a body positionable on a transmission line between an RF signal source and an RE device; 
 a conductive bolt positioned in the body that reflects a portion of a signal power of an RF signal from the RF signal source when the conductive bolt is in contact with a live conductor of the transmission line; and 
 a driving mechanism that causes the conductive bolt to contact the live conductor in response to a temperature at a measurement point colocated with the transmission line exceeding a threshold temperature. 
 
     
     
       23. The RF thermal fuse of  claim 22 , wherein the driving mechanism is irreversible. 
     
     
       24. The RE thermal fuse of  claim 23 , wherein the driving mechanism comprises:
 a spring that applies a force to the conductive bolt in a direction toward the live conductor; and 
 a solder that resists the force applied to the conductive bolt, wherein the solder comprises a soldering material having a melting temperature equal to the threshold temperature. 
 
     
     
       25. The RF thermal fuse of  claim 22 , wherein the driving mechanism is reversible. 
     
     
       26. The RF thermal fuse of  claim 25 , wherein the driving mechanism comprises a bimetal driving mechanism. 
     
     
       27. The RF thermal fuse of  claim 25 , wherein the driving mechanism comprises a chamber enclosing a gas or liquid, wherein the gas or the liquid is expandable such that the gas or the liquid applies pressure to the conductive bolt in response to the threshold temperature. 
     
     
       28. The RF thermal fuse of  claim 25 , wherein the driving mechanism comprises an electromagnet that opposes a force applied by a spring to the conductive bolt in a direction toward the live conductor in response to the electromagnet receiving a current from the RF device. 
     
     
       29. The RF thermal fuse of  claim 25 , wherein the driving mechanism comprises a shape memory alloy spring mechanism. 
     
     
       30. The RF thermal fuse of  claim 22 , further comprising a dielectric material positioned at a first end of the conductive bolt opposite a second end of the conductive bolt that contacts the live conductor. 
     
     
       31. A thermal protection system comprising:
 a plurality of RF thermal fuses, each RF thermal fuse comprising:
 a body positioned on a transmission line between an RF signal source and an RF device; 
 a conductive bolt positioned in the body; and 
 a driving mechanism that causes the conductive bolt to contact a live conductor of the transmission line in response to a temperature at a measurement point colocated with the transmission line exceeding a threshold temperature; 
 
 wherein the plurality of RF thermal fuses are positioned on the transmission line at intervals such that the plurality of RF thermal fuses are adapted to reflect a portion of the incident power of an RF signal in a predetermined frequency band from the RF signal source. 
 
     
     
       32. The thermal protection system of  claim 31 , wherein, for at least one of the plurality of RF thermal fuses, the driving mechanism is irreversible or reversible. 
     
     
       33. A system comprising:
 an RF device in communication with an RF signal source via a transmission line; 
 an RF thermal fuse positioned on the transmission line, the RF thermal fuse comprising:
 a body positioned on the transmission line between the RF signal source and the RF device; 
 a conductive bolt positioned in the body that reflects a portion of a signal power of an RF signal from the RF signal source when the conductive bolt is in contact with a live conductor of the transmission line; and 
 a driving mechanism that causes the conductive bolt to contact the live conductor in response to a temperature at a measurement point colocated with the transmission line exceeding a threshold temperature; 
 
 wherein the RF signal source reduces transmission power in response to the reflection of the portion of the signal power. 
 
     
     
       34. The system of  claim 33 , wherein the RF device comprises a thermal over-temperature protection fuse coupled to at least one component of the RF device, wherein a signal path is provided from the transmission line to the thermal over-temperature protection fuse via the at least one component, wherein the thermal over-temperature protection fuse opens the signal path in response to a temperature of the at least one component exceeding the threshold temperature. 
     
     
       35. The system of  claim 34 , wherein the thermal over-temperature protection fuse comprises a soldering material electrically connecting the thermal over-temperature protection fuse to the at least one component, wherein the soldering material has a melting temperature less than or equal to the threshold temperature.